Tripod leg clamp



July 2, w ADAMS TRIPOD LEG CLAMP Filed march zs, 1939 INVENTOR 5 ATTORNEYS BYWO/ Patented July 2, 1940 UNITE I TRIPOD LEG CLAMP Harry W. Adams, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application March 29,

9 Claims;

The present invention relates to tripods of the type generally used for supporting cameras, surveying instruments, and the like, which are provided with a plurality of extensible supporting 5 legs which comprise slidably united sections, and particularly to ameans for rigidly clam-ping these slidably united sections in any desired position.

The present invention is an improvement in the particular tripod leg clamping means disclosed in pending patent application, Serial Number 144,230, filed May 22, 1937, in the name of Joseph S. Beggs. While in appearance and in the manner of operation the clamping means constituting the present invention is similar to that disclosed in the noted patent application, it has been found that the herein disclosed tripod leg clamping means is much more simple in construction than that disclosed in said patent application without sacrificing any clamping effectiveness. In fact, it has been found that the present tripod leg clamping structure, due to its particular arrangement of parts, affords a clamping action as great, if not greater, than that of the clamping structure disclosed in the noted pending application with a lesser amount of force exerted by the operator.

Therefore, one object of the present invention is the provision of a clamping means for the telescoping legs of a tripod whichis easy to manipulate without inconvenience to the operator. Another object is the provision of a clamping means the operating handle of which can be used to adjust the telescoping leg sections into the desired position so that only one hand is required to adjust and clamp any one leg section. A further object is the provision of a clamp by means of which an adjustable leg can be frictionally-secured in any desired position rigidly enough to support a comparatively heavy weight. And still another is so designed that only a comparatively slight adjustment of the operating handle is required in altering the clamping means from a locking to an unlocking position. And another, and probably the main, object of the present invention is to provide a clamping means of the type described which possesses all of the above-noted advantages, and which is different and more simple than known clamping means claiming the same advantages.

The novel features that I consider characteristic of'my invention are set forth with particularityin the appended claims. The invention, itself, however, both as to its organization and its method of operation, together with additional object is the provision of a clamping means which 1939, Serial N0. 264,796

objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection 'With Fig. 4 is a rear elevation of one of the clamps,

and,

Fig. 5 is a section taken on line 55 of Fig. 1.

Like reference characters refer to corresponding parts throughout the drawing.

Referring now to the drawing, the numeral l0 designates a tripod head which is supported -by legs H. Each tripod leg comprises angular leg sections l2, to the upper ends of which are mounted brackets l 3. These brackets engage extensions M on the tripod head and are pivotally connected thereto by clamping bolts 15 by means of which the legs II can be held in any desired angular position relative to the tripod head. Angular leg sections l5 are connected at their lower ends by couplings I1 and diverge upwardlyin telescoping relation with respect to said angular leg sections I2, as shown clearly in Figs. 2-5. Bands l8 are fixed to the'lower ends of leg sections I 2 by screws H! to extend around and form a guide for the leg sections IE which telescope with the leg sections 12, see Fig. 5. Supporting feet, indicated at 9, can be removably attached to the couplings I"! in any suitable manner, said feet having pointed or rubber ends as may be desired.

' Inasmuch as'the clamps for each pair of telescoping leg sections IB and l 2 are identical, a description of one will suffice for both thereof. Embracing the upper end of each of the leg sections 16 is an angular stationary member 20 which is fastened to each of said leg sections l6 by any suitable means, such as rivets 2|. The angular stationary member 20 is fastened to the end of each of the leg sections 16 so that the end of each leg section is flush with the upper edge thereof, while the leg section li'. extends completely past said stationary member in telescoping relation with leg section l6. One end of the angular stationary member 20 extends beyond the side of the leg section I5 embraced thereby and constitutes the male member 22 of a separable hinge,

.of said nut member through here 2 1.

see Figs. 2-4. The other end of each angular stationary member extends beyond the other side of the leg section it embraced thereby, and provides a bearing portion 23 having a bore 24 extending therethrough.

The leg sections l2 and it are rigidly clamped together when the pressure member 25 is moved into and out of pressing engagement with the le section l2. One end of the pressure member 25 constitutes a female member 25 adapted to cooperate with said male member 22 and be held in hinged connection therewith by a hinge pin 21 passing through bores extending through said hinged parts, whereby said pressure member is pivoted to. said angular stationary member to move to and from a clamping position relative to said leg section. The pressure member 25 includes an angular portion 29 which extends into the vertex of the leg section l2, and which is adapted, when said pressure member is moved to its clamping position, to engage the faces of the arms of the leg section i2 adjacent the vertex thereof to force said leg section into frictional engagement with its telescoping leg section it.

" The angular portion 29 of the pressure member could be of a size and shape to completely fill the angular leg section I2, but since the frictional engagement between the telescoping leg sections is affected by moving the leg section 52 toward the leg section it substantially along the biseotor of the vertices thereof, no pressure at right angles to and against the entire walls of leg section I? is needed or would be effective. It will be appreciated that the most frictional engagement will be set up between the leg sections l2 and it if leg section i2 is moved toward leg section l8 along the bisector of the angles of the two. It is for this reason that the pressure member 25 is pivoted at the sides of the leg sections as shown. The hinge point of the pressure member 25 is so located that a point on the vertex of the angular portion 28 thereof will, in pivoting about said hinge point, scribe an are passing through the vertex of the leg section l2 whereby, due to the small amount of movement of the pressure member in moving between its locking and unlocking position, the angular portion of the pressure member in effect moves along the bisector of the vertex of the leg section l2. By this arrangement the leg section i2 is moved toward the'leg section It along the bisector of the vertices thereof, whereby a frictional engagement is set up between the entire surfaces of the two walls of each, and not over the surface of one wall as would be the case if leg section 12 were forced toward leg section it in a horizontal or vertical direction only.

The pressure member 25 is provided with a threaded bore 36 which is engaged by the threaded end 35 of the nut member 33. The nut member extends through and is rotatably mounted with respect to the bore 24 in the bearing portion 33 of the angular stationary member 28, and is provided with a flange 33 which engages the face of said bearing portion to prevent passage It will be readily understood that when the nut member 32 is rotated in one direction, the pressure member 25 will be drawn toward the bearing portion 23 causing it to pivot aboutits hinge point whereupon the angular portion 29 thereof will be moved into the vertex of leg section it. to force the same into frictional engagement with the leg section [6 to thereby clamp the leg in adjusting position, see Figs, 2 and 3. The rotation of the nut member in the opposite direction will move the pressure member 25 and the angular portion 29 away from the vertex and leg section l2 so that the leg section l6 can slide relative thereto. The bore 24 in bearing portion 23 is made sufliciently greater in diameter than the diameter of that part of the nut member passing therethrough to permit said nut member to move slightly laterally of said bore'to account for the slight arc of movement of the end of the pressure member into which said nut member is threaded. To prevent accidental removal of the nut member from the pressure member 25, the end thereof is adapted to extend completely therethrough and has a lock nut 35 screwed thereon.

Although the nut member 32 can be rotated in any manner to provide an adjustment of the pressure member 25, in order that simultaneous adjustment of the two pressure members 25 of each leg I I can be effected the following structure is provided. Each nut member 32 is provided with a hexagonal bore 36 into which the end of a hexagonal adjusting rod 31 extends so that the rod is slidable axially of the nut member, but cannot be rotated relative thereto. It is to be understood that the bore 36 of the nut member 32 and the adjusting rod 31 cooperating therewith can be of any complementary shape, such as triangular, rectangular, or the like, so long as a splined fitting is provided. A handle 33 is situated on the adjusting rod 31 intermediate the upper ends of the angular leg section l6 and has a hexagonal bore engaging said rod so that it can slide relative to the rod but cannot rotate V with respect thereto, see Figs. 1 and 2. Coil springs 39 encircle the rod 31 on either side of the handle 32, and have one end engaging the flange 33 of the nut member 32, and the other end seated in a recess 40 in the end of the handle I 38, which recesses are coaxial with the hexagonal bore therein. These springs tend to position the handle 38 on the rod 31 so that it will be equally spaced from each of the diverging leg sections l6 regardless of whether the leg is col- W lapsed or fully extended.

So that the rotation of the adjusting rod 3'! will effect a simultaneous clamping or unclamping action in each of the clamping mechanisms of any one leg H, the threads in the nut members 32 are formed oppositely. In other words, the

screw thread on one nut member 32 is left hand, while the screw thread on the other nut member is right hand. It was discovered that when the adjusting rod 31 is rotated, the right and left hand nut members did not always pick up their respective pressure members simultaneously, but one lagged slightly behind the other with the result that an uneven clamping occurred in the two clamps. spring washers 4! are positioned between the flanges 33 on each nut member 32 and the adjacent face of the bearing portion 23 of the stationary angular members .20, see Figs. 2 and 3; and these spring washers serve to equalize the pressure on the two clamps by allowing the nut members 32' to move relative to the pressure members 25 after said pressure members are in their clamping positions.

The above described clamping means oper-,

handle 38; the angular leg sections l6 and the' To overcome this fact, equalizing clamping means fixed thereto are pulled upward or shoved downward, as the case may be, by pulling or shoving on the handle 38, and when the desired position of extension is obtained the handle is rotated in the opposite direction to eiiect the clamping of the leg sections It will be appreciated that since this leg structure provides a clamping means w ereby the operating handle can be used to extend the legs as well as clamp the same in any desired position, one hand will sufiice to adjust and clamp the legs while the other may be used to steady the instrument mounted on the tripod head.

From the above description it will be understood that as the angular leg sections iii are extended from their collapsed position, see Fig; l, the two clamping means will be moved toward one another clue to the divergence of the leg sections. As the clamping means move toward or away from one another during adjustment of the legs H, the adjusting rod 3?! slides relative to the hexagonal bore in the nut members 32. The arrangement of parts is such that when the legs are collapsed and the leg sections iii are spaced apart the maximum distance, the ends of the adjusting rod 3? will not pull out of the bore 36 in the nut members 32; and when the legs are completely extended and the clamping means are the minimum distance apart, the nut members 32 will be long'enough to allow the ends of the rod 31 to pass thereinto without abutting the lock nut fixed on the end thereof.

It will be readily understood that a clamping means for telescoping leg sections as above set forth is easy to manipulate and provides a very rigid clamp with a slight amount of movement of the adjusting means. The particular arrangement of parts, although simple in construetion and easy to assemble, transmits pressure to the vertex of the angular leg section 92 in a manner and direction which provides a rigi lamping with the least amount of movement of the adjusting, handle.

Although I have shown and described one specific embodiment of the invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except in so far asis necessitated by the prior art and by the spirit of the appended claims.

Having thus described my invention what I claim is'new and desire to secure by Letters Patent of the United States is:

1. In a tripod having an adjustable leg formed of telescoping angular sections, means for frictionally clamping said sections together, said means comprising a stationary member embracing said angular sections and fixed to one thereof, a pressure member connected to said stationary member to move to and from a clamping position relative to said angular sections, said pressure member including a portion adapted to engage and apply pressure to the vertex of one of said angular sections when said pressure member is moved to its clamping'position, and adjusting means connected to said pressure member for moving the same to and from said clamping position.

2. In a tripod having an adjustable leg formed of telescoping angular sections, means for frictionally clamping said sections together, said means comprising a stationary member embracing said angular sections and fixed to one thereof, a pressure member including an angular portion adapted to engage the vertex of one of said angular sections, means for movably mounting said pressure member on said station ary member, whereby said pressure member may be moved to and from a clamping position relative to said angular sections, in which position angular portion is adapted to engage the vertex of one of said angular sections to force said angular section into frictional engagement with the other angular section, and adjusting means connected to said pressure member for moving the same to and from said clamping position.

3. In a tripod having an adjustable leg formed of telescoping angular'sections, means for frictionally clamping said sections together, said means comprising an angular stationary member embracing one of said angular sections and fixed thereto, one end of said angular stationary member extending beyond the end of said angular section to which it is fixed, a pressure member pivoted to the said end of said stationary member to move to and from a clamping position relative to said angular sections, said pressure member including an angular portion adapted to engage the vertex of one of said angular sections to force the same into clamping engagement with its telescoping section, and adjusting means connected to said pressure member for moving the same to and from said clamping position.

4. In a tripod having an adjustable leg formed of telescoping angular sections, means for frictionally clamping'said sections together, said means comprising an angular stationary member embracing one of said angular sections and fixed thereto, one end of said angular stationary member extending beyond the end of said angular section to which it is fixed, a pressure member pivoted to said end of said stationary member to move to and from a clamping position rela tive to said angular sections, said pressure member including an angular portion adapted to engage the vertex of one of said angular sections to force the same into clamping engagement with its telescoping section, and adjusting means connected to said pressure member for moving the same to and from said clamp-ing'position, said adjustin means including an adjusting member passing through said angular stationary member and connected to said pressure member, and means for adjusting said adjusting member to draw and repel said pressure member toward and from said angular stationary member respectively, whereby the same is moved to and from said clamping position.

5. In a tripod having anadjustable leg formed of telescoping angular sections, means for frictionally clamping said sections together, said means comprising an angular stationary member embracing one of said angular sections and fixed thereto, one end of said angular stationary member extending beyond the end of said angular section to which it is fixed, a pressure member pivoted to said end of said stationary member to move to and from a clamping position relative to said angular sections, said pressure member including an angular portion adapted to engage the vertex of one of said angular sections to force the same into clamping engagement with its telescoping section, and adjusting means connected to said pressure member for moving the same to and from said clamping position, said adjusting means including a nut passing through a bore in said angular stationary member and into threaded engagement with said pressure member, and means for rotating said nut to move the pressure member to and from said clamping position.

6. In a tripod having an adjustable leg formed of telescoping angular sections, means for frictionally clamping said sections together, said means comprising an angular stationary member embracing one of said angular sections and fixed to one end thereof, both ends of said angular stationary member extending beyond the ends of said angular section to which it is fixed, one of said ends constituting a hinge portion, and the other end provided with a bore extending therethrough substantially at right angles to said telescoping sections, a pressure member hinged at one end to said hinge portion of said angular stationary member to move to and from a clamping position relative to said angular sections, said pressure member including an angular portion adapted to engage the vertex of one of said angular sections to force the same into clamping engagement with its telescoping section, and adjusting means for moving said pressure member to and from its clamping position, said adjusting means including a nut extending through said bore and rotatable with respect to said angular stationary member, said nut being in threaded engagement with said pressure member and having a polygonal bore, and a polygonal rod slidable in said polygonal bore for rotating said nut to move the same to and from its clamping position.

7. In combination, a pair of telescoping angular sections, an angular stationary member embracing said angular sections and fixed to one thereof, a second pair of telescoping sections spaced from the first mentioned pair, an angular stationary member embracing the second pair of sections and fixed to one thereof, a pressure member connected to each of said angular stationary members to move to and from a clamping position relative to each pair of said telescoping sections, each pressure member including a portion adapted to extend into the vertex of one of the telescoping sections of each pair to engage and force said section into clamping engagement with its telescoping section when said pressure member is moved to its clamping position, an adjusting means connected to each of said pressure members for moving the same into and out of its clamping position, and a single operating member connecting both of said adjusting means, whereby the separate pressure members can be simultaneously moved to and from clamping position through the actuation thereof.

8. In combination, a pair of telescoping angular sections, an angular stationary member embracing said angular sections and fixed to one thereof, a second pair of telescoping sections spaced from the first mentioned pair, an angular stationary member embracing the second pair of sections and fixed to one thereof, a pressure member pivoted to each of said angular stationary members to move to and from a clamping position relative each pair of telescoping sections, each pressure member including an angular portion adapted to extend into the vertex of one of the telescoping sections of each pair thereof and adapted to engage and force the said angular section into clamping engagement with its telescoping section when said pressure member is moved to its clamping position, an adjusting means connected to each of said pressure members for moving the same into and out of its clamping position, and including a nut member extending through and rotatably mounted with respect to each of said angular stationary members, each of said nut members being in threaded engagement with the pressure member pivoted to its associated angular stationary member, whereby a rotation of each nut member is adapted to move its associated pressure member to and from its clamping position depending upon the direction of rotation, and a single operating member connecting both of said nut members whereby the separate pressure members can be simultaneously moved into and out of clamping position with their associated telescoping sections through the actuation thereof.

9. In combination, a pair of telescoping angular sections, an angular stationary member embracing said angular sections and fixed to one thereof, a second pair of telescoping sections spaced from the first mentioned pair, an angular stationary member embracing the second pair of sections and fixed to one thereof, a pressure member pivoted to each of said angular stationary members to move to and from a clamping position relative each pair of telescoping sections, each pressure member including an angular portion adapted to extend into the vertex of one of the telescoping sections of each pair thereof and adapted to engage and force the said angular section into clamping engagement with its telescoping section when said pressure member is moved to its clamping position, an adjusting means connected to each of said pressure members for moving the same into and out of its clamping position, and including a nut member extending through and rotatably mounted with respect to each of said angular stationary members, each of said nut members having a polygonal bore therethrough and being in threaded engagement with one of said pressure members, and a polygonal rod having its ends extending into the bores in the nut member, whereby a rotation of said rod will cause said nut members to rotate and move the pressure members to and from their clamping positions simultaneously depending upon the direction of rotation of said rod.

HARRY W. ADAMS. 

